It serves pretty much the same aim, i.e. production of energy by ATPase. One can thing about it as being flipped (inside-out) in comparison to mitochondria or as analogy with cristae being stroma.

One more thing that came to my mind. RuBISCO is activated by increase of Mg2+ concentration. I'm not sure how this proceeds, as it was always covered in lectures simply as increase of Mg2+ ions, but it could be related to chemiosmosis http://en.wikipedia.org/wiki/RuBisCO#Re ... c_activity

Chemiosmosis is relates to the generation of ATP by the movement of hydrogen ions across a membrane during cellular respiration.It will diffuse from an area of high proton concentration to an area of lower proton concentration. This could be harnessed to make ATP. He likened this process to osmosis, the diffusion of water across a membrane, which is called chemiosmosis.